The present invention relates to a system for performing on-off control of a power source of a terminal device at a preset time.
At present, point-of-sales (POS) systems are employed in department stores, supermarkets, etc. The POS system is constituted by one or a plurality of terminal devices such as one or a plurality of electronic cash registers provided at counters and a host apparatus having, for example, the same configuration as that of the terminal devices, to which the terminal devices are connected. When sale of commodities has been made at each of the terminal devices, inputted names, quantities, unit prices, a total price, etc. of the commodities are immediately transmitted to the host apparatus.
However, data which cannot be transmitted from the terminal devices to the host apparatus at the time of sales, for example, gross sales of one day may be transmitted to the host apparatus after closing of the shop at night. Thus, in the POS system, such a necessity arises frequently that the terminal devices are operated at night.
Two methods have been so far employed for controlling power sources of the terminal devices prior to use of the terminal devices. In one method, power source switches of the terminal devices are operated manually. In the other method, the power sources of the terminal devices are controlled in response to reception of a transmission signal outputted by the host apparatus, etc. Thus, conventionally, in the case where data transmission is performed between the host apparatus and the unattended terminal devices at night, the following two power source control methods can be employed. In one known power source control method, the power sources of the terminal devices are kept in the ON state at all times. In this known method, although data transmission from the terminal devices to the host apparatus can be started immediately, the power sources are in the ON state not only at the time of data transmission but also when the terminal devices are not in use, thereby resulting in waste of power consumption.
Meanwhile, in the other known power source control method, the power sources of the terminal devices are turned on in response to reception of an ON signal for turning on the power sources of the terminal devices, which ON signal is outputted by the host apparatus, etc. However, this prior art method has such a drawback that since the terminal devices perform reading of a transmitted program, etc. after turning on of the power sources, a long time period elapses from transmission of the ON signal by the host apparatus, etc. to actual start of data transmission.